External battery and satellite communication terminal

ABSTRACT

A device that can realize satellite communication with a popularized mobile phone in a case a large number of users communicate at a same time such as in a case where disaster strikes and the like. An external battery for charging a mobile phone includes a satellite antenna for performing satellite communication via a satellite communication channel and a satellite communication unit which causes the mobile phone to perform the satellite communication via the satellite antenna. The mobile phone and the external battery are connected with a cable and the like, and thereby a satellite communication terminal is configured.

TECHNICAL FIELD

The present invention relates to an external battery for charging amobile communication terminal such as a mobile phone and the like. Inparticular, the present invention relates to an external battery havinga function to cause a mobile communication terminal to perform satellitecommunication. Further, the present invention relates to a satellitecommunication terminal having the mobile communication terminal and theexternal battery.

BACKGROUND ART

In a case of contingencies such as disaster like earthquake in urbanarea, it is desired to promptly perform a rescue request and safetyconfirmation.

Presently, a lot of people have and always carry a mobile phone.Therefore, it is considered that a rescue request and safety informationcan be sent from the mobile phone to a disaster center and the like.However, in a case where disaster like earthquake occurs in urban area,a mobile communication channel might not be used due to the destructionof a base station and the like.

Patent literature 1 describes, in a case where disaster strikes, safetyconfirmation information can be collected from the mobile phones usingthe satellite communication channel. This makes possible to collectsafety confirmation information even when the mobile communicationchannel cannot be used due to the destruction of the base station andthe like.

CITATION LIST Patent literature

Patent Literature 1: JP2004-297131A

SUMMARY OF INVENTION Technical Problem

As described in Patent Literature 1, if the satellite communicationchannel can be used in a case where disaster strikes, a rescue requestand safety confirmation can be carried out promptly.

However, from a practical viewpoint, the frequency band is limited forthe mobile communication terminal of the mobile phone and the like toperform the satellite communication using the satellite communicationchannel. Therefore, in a case where disaster strikes and the like, it isimpossible to assign the frequency band sufficient to perform thesatellite communication by the mobile communication terminal of a largenumber of users at the same time.

If the sufficient frequency band is not assigned, the mobile phone isrequired to have a large amount of electric power to obtain thetransmission/reception power and a large antenna to obtain high antennagain for performing the satellite communication. However, thepopularized mobile phone is required to be downsized, so that thebattery with large power capacity and the large antenna cannot bemounted. Therefore, it is difficult to perform the satellitecommunication using the popularized mobile phone.

The present invention aims to achieve the satellite communication usingthe popularized mobile communication terminal in a case where a largenumber of users communicate at the same time such as in a case wheredisaster strikes and the like.

Solution to Problem

According to the present invention, an external battery that charges amobile communication terminal includes:

an electricity storage unit that stores electric power;

a charging unit that supplies the electric power stored in theelectricity storage unit to the mobile communication terminal to chargethe mobile communication terminal;

a satellite antenna to be used when performing satellite communicationvia a satellite communication channel; and

a satellite communication unit that causes the mobile communicationterminal to perform the satellite communication of message including aself-position via the satellite antenna.

Advantageous Effects of Invention

The external battery related to the present invention includes not onlya function to charge the mobile communication terminal, but also afunction to cause the mobile communication terminal to perform thesatellite communication.

Since the external battery does not have a number of functions like themobile communication terminal, it is possible to mount the battery withlarge power capacity and a large antenna, while suppressing thelargeness. Therefore, the external battery is combined with the mobilecommunication terminal, and thereby, in a case where a large number ofusers communicate at the same time such as in a case where disasterstrikes and the like, the satellite communication can be achieved by thepopularized mobile communication terminal.

Further, it is common to carry the external battery with the mobilecommunication terminal. Therefore, in a case of contingencies such aswhere disaster strikes and the like, the external battery is carriedwith the mobile communication terminal, and thus a rescue request andthe like can be performed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration diagram of a satellite communication terminal100 related to a first embodiment.

FIG. 2 is a flowchart showing an operation of the satellitecommunication terminal 100 related to the first embodiment.

FIG. 3 is a configuration diagram of a satellite communication terminal100 related to a fourth embodiment.

FIG. 4 is a flowchart showing an operation of the satellitecommunication terminal 100 related to the fourth embodiment.

FIG. 5 is a configuration diagram of a satellite communication terminal100 related to a fifth embodiment.

FIG. 6 is a flowchart showing an operation of the satellitecommunication terminal 100 related to the fifth embodiment.

FIG. 7 is a configuration diagram of a satellite communication terminal100 related to a sixth embodiment.

FIG. 8 is a configuration diagram of a satellite communication terminal100 related to a seventh embodiment.

FIG. 9 is a configuration diagram of a satellite communication system200 related to an eighth embodiment.

DESCRIPTION OF EMBODIMENTS Embodiment 1

FIG. 1 is a configuration diagram of a satellite communication terminal100 related to a first embodiment.

The satellite communication terminal 100 includes a mobile phone 10(mobile communication terminal) such as smartphones and an externalbattery 20 for charging the mobile phone 10. The mobile phone 10 and theexternal battery 20 are connected via a cable 30.

The mobile phone 10 includes an electricity storage unit 11, a mobileantenna 12, a mobile communication unit 13, a control unit 14, an inputunit 15, an output unit 16, and a connection unit 17.

The electricity storage unit 11 is an electric storage device such aslithium-ion battery for storing electric power to drive the mobile phone10. The mobile antenna 12 is an antenna for performing communication(mobile communication, hereinafter) by a mobile communication channelwhich passes through a ground-based base station and the like. Themobile communication unit 13 is a function to perform the mobilecommunication via the mobile antenna 12. The control unit 14 is aprocessing device such as CPU which carries out various controlaccording to inputs from the input unit 15 and the like. The input unit15 is an input device such as a keyboard, a microphone, and the like forinputting character data, voice data, and the like. The output unit 16is an output device such as an LCD, a speaker, and the like foroutputting character data, voice data, and the like. The connection unit17 is a connecting device for connecting to the electric power sourceand instruments such as the external battery 20; a cable 30 of USBstandard and the like which can be used for both of supplying theelectric power and transmitting signals is connected.

The external battery 20 includes an electricity storage unit 21, asatellite antenna 22, a charging unit 23, a satellite communication unit24, and a selection unit 25.

The electricity storage unit 21 is an electric storage device such aslithium-ion battery which stores electric power for charging the mobilephone 10 as well as for driving the external battery 20. The satelliteantenna 22 is an antenna for performing communication (satellitecommunication, hereinafter) using the satellite communication channelvia quasi-zenith satellites. The charging unit 23 is a function tosupply the electric power stored in the electricity storage unit 21 tothe mobile phone 10 and to charge the electricity storage unit 11 of themobile phone 10. The satellite communication unit 24 is a function tocause the mobile phone 10 to perform the satellite communication via thesatellite antenna 22. The selection unit 25 is a function to make aselection of at least either of a charge mode for causing the chargingunit 23 to charge and a communication mode for causing the satellitecommunication unit 24 to perform the satellite communication accordingto inputs from the input unit 15 and the like.

Here, functions explained above may be implemented by, for instance,software and the like. In this case, the software for implementing thefunctions may be stored in memory devices such as ROM, RAM or the like,and read and executed by the processing device such as CPU. Further, thefunctions may be implemented not by software but by circuits, devices,and the like.

FIG. 2 is a flowchart showing an operation of the satellitecommunication terminal 100 related to the first embodiment. FIG. 2 showsthe operation of a case where the external battery 20 is connected tothe connection unit 17.

Upon connecting the external battery 20 to the connection unit 17, theselection unit 25 is started; the selection unit 25 instructs the mobilephone 10 to select either of the charge mode and the communication mode(S11). Then, the control unit 14 receives the instruction, outputs themessage to the output unit 16 (for instance, displays the message onLCD), and prompts the user to select either of the charge mode and thecommunication mode (S12). Then, according to the operation of the user,the input unit 15 selects at least either of the charge mode and thecommunication mode (S13).

If the charge mode is selected at S13, the charging unit 23 is startedby the control unit 14, the charging unit 23 supplies the electric powerstored in the electricity storage unit 21 to the mobile phone 10 tocharge the electricity storage unit 11 (S14).

On the other hand, if the communication mode is selected at S13, thesatellite communication unit 24 is started by the control unit 14, thesatellite communication unit 24 connects the mobile phone 10 to thesatellite communication channel via the satellite antenna 22 (S15). Themobile phone 10, when connected to the satellite communication channel,using the input unit 15 and the output unit 16, performs the satellitecommunication of transmission/receipt of the message with thepredetermined number of characters or less including information showinga self-position and the like.

Here, at the normal time where the external battery 20 is not connectedto the connection unit 17 of the mobile phone 10, the mobile phone 10works as a general mobile phone. That is, at the normal time, the mobilecommunication unit 13 is started by the control unit 14, and the mobilephone 10 is connected to the mobile communication channel via the mobileantenna 12. Then, voice call, transmission/receipt of electronic mail,browsing websites, downloading application software and the like arecarried out using the input unit 15 and the output unit 16.

Further, even when being charged at S14, the mobile phone 10 also worksas the general mobile phone.

Here, the mobile phone 10 is not a particular one for performing thesatellite communication, but a popularly used mobile phone. The generalmobile phone 10 has been required to be multi-functional and as well tobe downsized. Therefore, the electricity storage unit 11 cannot beenlarged; and it is impossible to store the sufficient electric power toperform the satellite communication using the narrow communication bandin the electricity storage unit 11. Further, a large antenna forperforming the satellite communication cannot be mounted on the mobilephone 10.

However, the external battery 20 is not required to be multi-functionalor downsized like the mobile phone 10. Therefore, the electricitystorage unit 21 can be enlarged to some extent, which enables to storethe sufficient electric power to perform the satellite communicationusing the narrow communication band. Even if the electricity storageunit 21 cannot store the sufficient electric power, the electric powerstored in the electricity storage unit 11 and the electric power storedin the electricity storage unit 21 can be combined to make thesufficient electric power. Further, a large antenna (satellite antenna22) for performing the satellite communication can be mounted on theexternal battery 20.

As discussed above, in the satellite communication terminal 100 relatedto the first embodiment, the satellite antenna 22 and the like ismounted on the external battery 20, so that the satellite communicationis achieved by working the mobile phone 10 and the external battery 20together.

By the above, a weak spot that only the popularized mobile phone 10cannot supply sufficient transmission/reception power and antenna gainis supplemented by the external battery 20, which enables the satellitecommunication by the popularized mobile phone 10.

As a result of this, in a case where disaster strikes and the like, alarge number of users try to communicate at the same time, which enablesthe satellite communication by the popularized mobile phone 10. Inparticular, since the transmission/reception power and the antenna gainare high, the satellite communication is possible even in a circumstancewhere obstacles exist such as woods or nibbles. Further, even in a casewhere the satellite communication itself is difficult due to nibbles orshielding, it is possible to provide a rescue signal for rescueoperation by a search party.

Here, it is desired to carry the external battery 20 with the mobilephone 10. Therefore, even if a large electricity storage unit 21 isdesired, it is not possible to make it too large to carry. Similarly,even if a large antenna is desired, it is not possible to make it toolarge to carry

However, since the external battery 20 is not multi-functional such asthe mobile phone 10, there is no need to mount many components on theexternal battery 20. Further, the external battery 20 is rarelymanipulated by hand like the mobile phone 10, and usually contained in abag and the like. Therefore, if the external battery 20 and the mobilephone 10 are made to have similar size, it is possible to mount a largerelectricity storage unit or a larger antenna on the external battery 20.

Further, in the above explanation, a cable 30 that can be used for bothof the power supply and the signal transmission is connected to theconnection unit 17. However, two cables of a cable for the power supplyand a cable for the signal transmission can be connected to theconnection unit 17. Further, in case of the satellite communication, thecable 30 is not connected to the connection unit 17, but wirelessconnection can be achieved.

Further, in the above explanation, in case of the satellitecommunication, messages with the predetermined number of characters orless are transmitted/received. However, it is also possible totransmit/receive voice calls or image data. However, as described above,since a sufficient frequency band is not assigned, the communicationwith large data amount might be difficult. Therefore, the communicationwith suppressed data amount is desired.

Further, in order to work the popularized mobile phone 10 and theexternal battery 20 together, additional functions may be required inthe mobile phone 10. In this case, for instance, application softwarefor implementing the additional functions can be downloaded from apredetermined website and the like to be installed by the mobile phone10. Obviously, not limited to the above, additional functions may beintroduced to the mobile phone 10 in some manners.

Further, in the above explanation, quasi-zenith satellites are used forthe satellite in the satellite communication. Not limited to this, thesatellite communication can be mediated by another satellite such as ageostationary satellite. However, since the quasi-zenith satellite islocated at the zenith with a high elevation angle, it is possible tosecure the communication channel under a circumstance where thecommunication eyesight to the geostationary satellite is interrupted dueto the mountain shade or building shade and the like. Therefore, arescue request can be achieved from mountain area or urban area.

Further, an S band, for example, is used as the frequency band for thesatellite communication. The S band is the frequency band which isallowed to use by the mobile communication among the satellitecommunication channels, and further, it is possible to obtainsufficiently effective transmission/receipt sensitivity by the antennawith a dimension of around 50 mm×50 mm×5 mm for the mobilecommunication. Therefore, it is easy to implement this antenna on theexternal battery 20.

Further, in the above explanation, on connecting to the satellitecommunication channel, the mobile phone 10 performs the satellitecommunication such as the transmission/reception of the messages and thelike.

Here, in case of sending a message, when the external battery 20receives a transmission instruction from the mobile phone 10, theinstructed message is sent via the satellite communication channel. Thatis, the external battery 20 works by receiving the instruction from themobile phone 10.

On the other hand, in case of receiving the message, when receiving themessage via the satellite communication channel, the external battery 20sends the message to the mobile phone 10. That is, the external battery20, on receiving the message via the satellite communication channel,sends the message to the mobile phone 10 even when no instruction fromthe mobile phone 10 is received to obtain the message. Therefore, it isunnecessary for the mobile phone 10 to periodically check if theexternal battery 20 receives the message or not; and the mobile phone 10may become sleep state. Therefore, the power consumption of the mobilephone 10 can be suppressed.

Here, when the external battery 20 sends the message to the mobile phone10, if the mobile phone 10 is in the sleep state, the external battery20 may activate the mobile phone 10 and send the message to the mobilephone 10. For instance, the above operation can be performed if themobile phone 10 is set to receive the activation signal from theexternal battery 20 even when the mobile phone 10 is in the sleep state.

Further, in the above explanation, either of the charge mode and thecommunication mode is selected. However, the charge mode and thecommunication mode can be selected at the same time. In this case, thesatellite communication can be performed by the mobile phone 10, whilethe electricity storage unit 11 is being charged. Therefore, thesatellite communication can be performed by the mobile phone 10 even ifthe electricity storage unit 11 stores less amount of electric power.

Further, in the above explanation, the mobile phone 10 is an example ofa mobile communication terminal. However, another type of communicationterminal other than the mobile phone 10 may be used as long as it iscarried by the user.

Embodiment 2

In the first embodiment, it is explained that the user is prompted toselect the charge mode and the communication mode. In the secondembodiment, the charge mode and the communication mode can be selectedautomatically according to whether or not an emergency broadcast signalis received from the satellite.

A part being different from the first embodiment will be mainlyexplained in the second embodiment.

In the first embodiment, at S11 to S13 of FIG. 2, the user is promptedto select the charge mode or the communication mode.

On the contrary to this, in the second embodiment, when the externalbattery 20 is connected, according to whether or not a satellitecommunication unit 24 receives the emergency broadcast signal from thesatellite, a selection unit 25 selects the charge mode or thecommunication mode. Specifically, the selection unit 25, when theexternal battery 20 is connected, selects the charge mode if theemergency broadcast signal is not received, and selects thecommunication mode if the emergency broadcast signal is received.

Further, if the external battery 20 is connected to the mobile phone 10and the charge mode is being selected, when the satellite communicationunit 24 receives the emergency broadcast signal, the selection unit 25switches the charge mode to the communication mode.

For instance, in a case where disaster strikes and the like, theemergency broadcast signal is sent from the satellite to make thecommunication mode be automatically selected. Because, in a case wheredisaster strikes and the like, there may be a case where the operationto select the communication mode is bothersome or difficult.

As discussed above, in the satellite communication terminal 100 relatedto the second embodiment, according to whether or not the emergencybroadcast signal is received from the satellite, the charge mode or thecommunication mode can be selected automatically. Therefore, the userdoes not need to do the bothersome operation, which improves theconvenience.

Here, the external battery 20 may be provided with a display device suchas an LCD, and when the emergency broadcast signal is received, thereceipt of the emergency broadcast signal may be displayed to notify theuser. Further, the external battery 20 may be provided with a speaker,and when the emergency broadcast signal is received, the receipt of theemergency broadcast signal may be notified to the user by sound.

Further, there may be a case where without receiving the emergencybroadcast signal, it is necessary to perform the satellite communicationby some reason. Therefore, for instance, the charge mode and thecommunication mode may be switched according to the operation of theuser from an input unit 15.

Embodiment 3

In the second embodiment, according to whether or not the emergencybroadcast signal is received from the satellite, the charge mode or thecommunication mode can be selected automatically. In the thirdembodiment, it will be explained that the charge mode or thecommunication mode can be selected automatically according to whether ornot the mobile communication can be performed.

In the third embodiment, a part being different from the firstembodiment will be mainly explained.

In the first embodiment, at S11 to S13 of FIG. 2, the user is promptedto select the charge mode or the communication mode.

On the contrary to the above, in the third embodiment, when the externalbattery 20 is connected, the selection unit 25 selects the charge modeor the communication mode according to whether or not the mobile phone10 can perform the mobile communication via the mobile antenna 12.Specifically, the selection unit 25, when the external battery 20 isconnected, if the mobile communication is available, selects the chargemode, and if the mobile communication is not available, selects thecommunication mode.

Further, when the external battery 20 is connected to the mobile phone10, and when the charge mode is being selected, if the state in whichthe mobile communication is not available continues for a certain timeperiod or more, it is also possible to switch to the communication mode.

The state in which the mobile communication is not available is, forinstance, a case where electrical wave for the mobile communicationcannot be received continuously for equal to or greater than a certaintime period or where the mobile communication channel is in congestionstate.

The above control is performed because, in a case where the mobilecommunication is available, the necessity of the satellite communicationis low, and thus the user does not need to be prompted to select thecharge mode or the communication mode. In particular, in a case wheredisaster strikes and the like, there may be a case where the operationto select the communication mode is bothersome or difficult.

As discussed above, in the satellite communication terminal 100 relatedto the third embodiment, the charge mode or the communication mode canbe selected automatically according to the state of the mobilecommunication. Therefore, the user does not need to do the bothersomeoperation, which improves the convenience.

Here, even if the mobile communication is available, the satellitecommunication might be necessary for some reason. Therefore, forinstance, the charge mode and the communication mode can be switchedaccording to the operation of the user from the input unit 15.

Embodiment 4

The fourth embodiment will explain that authentication is performed atthe time of the satellite communication.

In the fourth embodiment, a part being different from the firstembodiment will be mainly explained.

FIG. 3 is a configuration diagram of the satellite communicationterminal 100 related to the fourth embodiment.

The satellite communication terminal 100 shown in FIG. 3 includes, inaddition to the configuration of the satellite communication terminal100 shown in FIG. 1, an authentication unit 26 in the external battery20.

The authentication unit 26 carries out user authentication by making theuser enter an ID and a password and the like.

FIG. 4 is a flowchart showing an operation of the satellitecommunication terminal 100 related to the fourth embodiment. FIG. 4shows the operation when the external battery 20 is connected to theconnection unit 17; and similarly to the first embodiment, when theexternal battery 20 is connected, the user is prompted to select thecharge mode or the communication mode.

The operations from S21 to S24 are the same as the ones from S11 to S14shown in FIG. 2, and the explanation will be omitted.

When the communication mode is selected at S23, the authentication unit26 instructs the mobile phone 10 to enter the ID and password (S25).Then, the control unit 14 receives the instruction, outputs the messageto the output unit 16, and prompts the user to enter the ID and password(S26). According to the operation of the user, the input unit 15 inputsthe ID and password (S27). The authentication unit 26 carries out theuser authentication based on the entered ID and password and the ID andpassword which have been previously registered (S28).

If the user authentication succeeded at S28, the satellite communicationunit 24 is started by the control unit 14, the satellite communicationunit 24 connects the mobile phone 10 to the satellite communicationchannel via the satellite antenna 22 (S29). On the other hand, if theuser authentication failed at S28, the satellite communication is notallowed and the mobile phone 10 is not connected to the satellitecommunication channel.

In the above explanation, if the user authentication failed, thesatellite communication is not allowed. However, in case of emergencysuch as when a rescue request is issued, there may be a case where it isbetter that the satellite communication is made available regardless ofwhether or not the user authentication succeeded. Then, if the userauthentication failed, the satellite communication may be made possibleto communicate with only a predetermined communication partner.

Further, in the above explanation, similarly to the first embodiment,when the external battery 20 is connected, the user is prompted toselect the charge mode or the communication mode. However, similarly tothe second embodiment, when the external battery 20 is connected, thecharge mode or the communication mode can be selected according to thestate of the mobile communication. In this case, after the communicationmode is selected, until the user authentication is carried out, thesatellite communication can be limited with only a predeterminedcommunication partner; and if the user authentication succeeds, thesatellite communication can be performed with an arbitrary communicationpartner.

As discussed above, in the satellite communication terminal 100 relatedto the fourth embodiment, if the user authentication succeeds, themobile phone 10 is allowed to perform the satellite communication.Therefore, it is possible to prevent a person other than the registereduser from performing the satellite communication.

On the other hand, a person other than the registered user can performthe satellite communication with the predetermined communicationpartner. Therefore, anyone can perform a rescue request and the like incase of emergency.

Further, the user authentication is carried out, thereby specifying auser who has performed the satellite communication. Therefore, thespecified user can be charged for the satellite communication. Here, thecharging can be paid in arrears or in advance.

Further, the authentication unit 26 may carry out, not limited to theauthentication using the ID and password, the user authentication byanother method such as the biometric authentication.

Embodiment 5

The fifth embodiment will explain that the external battery 20 furtherincludes an antenna that receives positioning signals from thesatellites such as the quasi-zenith satellites.

In the fifth embodiment, a part being different from the firstembodiment will be mainly explained.

FIG. 5 is a configuration diagram of the satellite communicationterminal 100 related to the fifth embodiment.

As for the configuration of the satellite communication terminal 100shown in FIG. 5, in addition to the configuration of the satellitecommunication terminal 100 shown in FIG. 1, the mobile phone 10 includesa positioning unit 18, and the external battery 20 includes a signalreception unit 27.

The positioning unit 18 is a function to specify the location of thesatellite communication terminal 100 based on the positioning signalsent from the satellite. The positioning signal includes a positioningsupplemental signal that is used for measuring the distance and apositioning reinforcing signal including information that contributesthe improvement of the accuracy. Here, the positioning signal mayinclude both or either of the positioning supplemental signal and thepositioning reinforcing signal.

The signal reception unit 27 is an antenna that receives the positioningsignals sent from the satellites such as the quasi-zenith satellites. Inparticular, the signal reception unit 27 is an antenna that can receivethe positioning signals of a plurality of frequency bands. For instance,the signal reception unit 27 is an antenna that can receive the L1 bandand the L2 band, or an antenna that can receive the L1 band and the L5band.

FIG. 6 is a flowchart showing an operation of the satellitecommunication terminal 100 related to the fifth embodiment. FIG. 6 showsthe operation of a case where the external battery 20 is connected tothe connection unit 17; similarly to the first embodiment, FIG. 6 showsthe operation of prompting the user to select between the charge modeand the communication mode in a case where the external battery 20 isconnected.

The operations from S31 to S35 are the same as the ones from S11 to S15shown in FIG. 2, and thus the explanation will be omitted.

In a case where the communication mode is selected at S33, subsequent toS35, the signal reception unit 27 is started by the control unit 14, thesignal reception unit 27 receives the positioning signal and sends thesignal to the mobile phone 10 (at S36). Then, the positioning unit 18specifies the location of the satellite communication terminal 100 basedon the positioning signal received by the signal reception unit 27(S37). The location information showing the location of the specifiedsatellite communication terminal 100 may be sent to the communicationpartner via the satellite communication according to an input from theinput unit 15.

As discussed above, in the satellite communication terminal 100 relatedto the fifth embodiment, the external battery 20 includes the signalreception unit 27. In the disaster center and the like which receivesthe rescue request, it is necessary to specify the location of therequester. The external battery 20 is provided with the signal receptionunit 27, which enables to specify the location of the requester, and thespecified location can be informed to the disaster center and the like.

Here, some popularized mobile phones 10 include a GPS (GlobalPositioning System) antenna.

However, the antenna provided to the popularized mobile phone 10, sincea large antenna cannot be mounted due to the downsizing request and thelike for the mobile phone 10, is a one frequency antenna. Therefore, thepositioning accuracy is low.

Further, the popularized mobile phone 10 specifies the location by anassisted GPS. In a case where disaster strikes and the like, when theground station is damaged, the assisted GPS might become impossible touse. Then, continuous positioning by the satellite becomes necessary,which requires frequent receipt of positioning signals. As a result ofthis, the electric power of the mobile phone 10 is consumed in a shorttime.

On the contrary to the above, in a case where the external battery 20 isprovided with the signal reception unit 27, a large antenna can be used,and thus the signal reception unit 27 can receive the positioningsignals of a plurality of frequency bands. Therefore, the positioningaccuracy can be improved. Further, the positioning signal is received bythe external battery 20, so that the power consumption of the mobilephone 10 can be suppressed.

In the above explanation, the positioning unit 18 provided to the mobilephone 10 specifies the location based on the positioning signal.However, the function to specify the location based on the positioningsignal may be included in the external battery 20, and the location maybe specified by the external battery 20. The above operation can furthersuppress the power consumption of the mobile phone 10.

Further, in the above explanation, when the communication mode isselected, the signal reception unit 27 receives the positioning signal.However, regardless of whether or not the communication mode isselected, when the positioning accuracy obtained by the configuration ofthe mobile phone 10 itself (the positioning function included in themobile phone 10) becomes low, the mobile phone 10 may issue a request tostart the signal reception unit 27. In another way, in a case where theremaining power of the electricity storage unit 11 becomes equal to orless than a certain amount, the mobile phone 10 may issue a request tostart the signal reception unit 27. Then, the signal reception unit 27can receive the signal reception unit 27 in a case where the startingrequest is issued from the mobile phone 10.

The case where the positioning accuracy obtained by the configuration ofthe mobile phone 10 itself becomes low is, for instance, when theassisted GPS cannot be used, that is, the positioning information cannotbe obtained via the ground station, and the like.

Further, the signal reception unit 27, on receiving the positioningsignal, even if the instruction to obtain the positioning signal is notreceived from the mobile phone 10, sends the positioning signal to themobile phone 10. Therefore, the mobile phone 10 does not need toperiodically check whether or not the external battery 20 receives thepositioning signal, and the mobile phone 10 can be in the sleep state.Therefore, the power consumption of the mobile phone 10 can besuppressed.

Embodiment 6

The sixth embodiment will explain that the external battery 20 furtherincludes a function to measure biological information such as bloodpressure, pulsation, blood glucose level and the like.

FIG. 7 is a configuration diagram of a satellite communication terminal100 related to the sixth embodiment.

The satellite communication terminal 100 shown in FIG. 7 includes, inaddition to the configuration of the satellite communication terminal100 shown in FIG. 1, a measurement unit 28 in the external battery 20.

The measurement unit 28 is a measurement device to measure biologicalinformation such as blood pressure, pulsation, blood glucose level andthe like.

For instance, the user suffering from disease, in a case where disasterstrikes and the like, the biological information is measured by themeasurement unit 28 and sent to the disaster center via the satellitecommunication. The above operation enables to confirm the status of theuser's disease at the disaster center, and an appropriate treatment canbe taken. Here, in a case where an abnormal acceleration is detected byacceleration information obtained by processing the positioning signal,it is also possible to react similarly by treating the abnormalacceleration as accident detection information; at this time, it isneedless to say that it can be the starting request from the sleepstate.

Here, the measurement unit 28 may previously store the user's personalhospital and the like as a destination of the information. In this case,the biological information is sent not to the disaster center, but tothe destination registered previously; and thereby it is possible tocheck the status of user's disease more appropriately.

As discussed above, in the satellite communication terminal 100 relatedto the sixth embodiment, the satellite communication terminal 100includes the measurement unit 28. Based on the biological informationmeasured by the measurement unit 28, it is possible to understand thestatus of the user's disease, and to go to rescue the user withnecessary instruments and the like.

Here, not limited to a case where disaster strikes, but also at thenormal time, the biological information measured by the measurement unit28 can be sent to the user's personal hospital, and thereby an ambulancecan be deployed.

Embodiment 7

The seventh embodiment, it will be explained that route informationshowing an escape route and the like is stored in the external battery20.

In the seventh embodiment, a part being different from the firstembodiment will be mainly explained.

FIG. 8 is a configuration diagram of a satellite communication terminal100 related to the seventh embodiment.

The satellite communication terminal 100 shown in FIG. 8 includes, inaddition to the configuration of the satellite communication terminal100 shown in FIG. 1, a memory unit 29 in the external battery 20.

The memory unit 29 is a memory device which stores map information,route information showing an escape route for a case where disasterstrikes and the like, information required for securing lifelines, andthe like.

The satellite communication terminal 100 is used at the time ofcontingencies such as a case where disaster strikes and the like.Therefore, the information required in a case where disaster strikes andthe like is previously stored, and outputted from the output unit 16 ofthe mobile phone 10.

Here, at the normal time, the map information, the route information,the information required for securing lifelines, and the like can beobtained from a predetermined website, etc. via the mobile communicationor the satellite communication, and such information can be stored inthe memory unit 29.

As discussed above, the satellite communication terminal 100 related tothe seventh embodiment stores the information required in a case wheredisaster strikes and the like in the external battery 20. Therefore, ina case where disaster strikes and the like, necessary information can beobtained without performing the communication.

Embodiment 8

The eighth embodiment will explain a satellite communication system 200using the satellite communication terminal 100 that has been explainedin the first through sixth embodiments.

FIG. 9 is a configuration diagram of the satellite communication system200 related to the eighth embodiment.

The satellite communication system 200 includes a satellitecommunication terminal 100, a quasi-zenith satellite 110, a quasi-zenithsatellite antenna station 120, a quasi-zenith satellite operationcontrol station 130, and a disaster center 140.

The satellite communication terminal 100 is the one which has beenexplained in the first to fifth embodiments. The quasi-zenith satellite110 is a satellite which stays over a particular area for a long timeand takes the quasi-zenith orbit. The quasi-zenith satellite antennastation 120 is a facility settled on the ground having an antenna fortransmitting/receiving data to/from the quasi-zenith satellite 3. It isa facility which relays data sent/received by the antenna of thequasi-zenith satellite antenna station 120. The disaster center 140 is afacility which receives the rescue requests and collects the safetyinformation.

In a case where disaster strikes and the like, the satellitecommunication terminal 100 communicates with the disaster center 140through the satellite communication via the quasi-zenith satellite 110,the quasi-zenith satellite antenna station 120, and the quasi-zenithsatellite operation control station 130. Then, the rescue request andthe safety information are sent to the satellite communication terminal100.

For instance, in a case where the rescue is requested, the satellitecommunication terminal 100 conveys the status of the site (for instance,the number of injured persons or the conditions of the injured), notonly requests the rescue, to the disaster center 140. Further, from thedisaster center 140, the information such as within how many minutes therescue could reach the site, how to do first aid and the like isconveyed to the satellite communication terminal 100.

Here, in the above explanation, the satellite communication system 200which requests the rescue and the like using the satellite communicationterminal 100 has been discussed. Here, COSPAS-SARSAT is known as asystem which requests the rescue using the satellite communicationchannel.

In this system, when a beacon transmitter which is called E-PIRB(Emergency Position Indicating Radio Beacon) mounted on a ship takeswater because of a ship accident and the like, a signal of the rescuesignal is issued from the beacon transmitter. The issued signal isdetected by the geostationary satellite, and circular orbit satellitesmeasure the location of the issued signal. By this operation, theoccurrence of the ship accident and the location of the accident arespecified, and immediate rescue activities can be implemented.

This search and rescue system has been also applied to the use on theground. For instance, in a case of distress in mountaineering and thelike, when a mountain climber issues a signal of rescue request by a PLB(Personal Locator Beacon), the issued signal is detected by thegeostationary satellite, and circular orbit satellites measure thelocation of the issued signal.

In this search and rescue system, only the transmitter issues thesignal, and there is no means to convey additional information such asthe status of the accident site. Further, in this search and rescuesystem, the signal is sent unidirectionally from the accident site, andthe information cannot be sent from the rescue side to the accidentsite.

Further, E-PIRB and PLB are dedicated terminals for rescue request. Thiskind of dedicated terminals for rescue request are carried only atspecial occasion such as mountain climbing and the like, and suchterminals are not always carried. Therefore, in a case of contingencieswhere a disaster like earthquake occurs in urban area, such terminalsrarely be carried; and such terminals never be used as a terminal forthe rescue request at the time of contingencies.

On the contrary to the above, in the satellite communication system 200,the satellite communication terminal 100 can convey the additionalinformation, and the bi-directional communication can be performed withthe disaster center 140. Further, the mobile phone 10 and the externalbattery 20 which form the satellite communication terminal 100 are to bealways carried.

Further, in the above explanation, the transmission/reception power andthe antenna gain of the mobile phone 10 are increased, and therebyenabling the satellite communication in the narrow communication band.Without increasing the transmission/reception power and the antenna gainof the mobile phone 10, the satellite communication can be performed byenlarging the antenna at the satellite side.

However, if the antenna at the satellite side is enlarged, thetransmission area of the signals from the satellite becomes narrow, andthus the satellite communication area becomes also narrow. Further, asexplained in the fifth embodiment, in a case where the satellites sendthe positioning signals, the positioning accuracy based on thepositioning signals becomes low.

Therefore, it is difficult to enlarge the antenna at the satellite sideto configure the satellite communication system 200.

Up to the above, the embodiments of the present invention have beenexplained; among the embodiments, two or more embodiments can becombined and implemented. In another way, among these embodiments, oneembodiment can be partially implemented. In another way, among theseembodiments, two or more embodiments can be partially combined andimplemented. Here, the present invention is not limited to theseembodiments, but various modifications can be done according to thenecessity.

REFERENCE SIGNS LIST

10: mobile phone; 11: electricity storage unit; 12: mobile antenna; 13:mobile communication unit; 14: control unit; 15: input unit; 16: outputunit; 17: connection unit; 18: positioning unit; 20: external battery;21: electricity storage unit; 22: satellite antenna; 23: charging unit;24: satellite communication unit; 25: selection unit; 26: authenticationunit; 27: signal reception unit; 28: measurement unit; 29: memory unit;30: cable; 100: satellite communication terminal; 110: quasi-zenithsatellite; 120: quasi-zenith satellite antenna station; 130:quasi-zenith satellite control station; 140: disaster center; and 200:satellite communication system.

1. An external battery that charges a mobile communication terminalcomprising: an electricity storage unit that stores electric power; acharging unit that supplies the electric power stored in the electricitystorage unit to the mobile communication terminal to charge the mobilecommunication terminal; a satellite antenna to be used when performingsatellite communication via a satellite communication channel; and asatellite communication unit that causes the mobile communicationterminal to perform the satellite communication of message including aself-position via the satellite antenna.
 2. The external battery ofclaim 1, further comprising: a selection unit that selects at least oneof a charge mode to cause the charging unit to charge and acommunication mode to cause the satellite communication unit to performthe satellite communication.
 3. The external battery of claim 2, whereinthe selection unit, when receiving a predetermined signal via thesatellite communication, selects the communication mode.
 4. The externalbattery of claim 3, further comprising: an authentication unit thatperforms user authentication, wherein the satellite communication unitcauses to perform the satellite communication in cases where theauthentication unit succeeds the user authentication and where thepredetermined signal is received via the satellite communication.
 5. Theexternal battery of claim 2, wherein the mobile communication terminalincludes a mobile antenna to be used when performing mobilecommunication via a mobile communication channel, and wherein theselection unit selects the communication mode in a case where the mobilecommunication is not available via the mobile antenna.
 6. The externalbattery of claim 5, further comprising: an authentication unit thatperforms user authentication, wherein the satellite communication unitcauses to perform the satellite communication in cases where theauthentication unit succeeds the user authentication and where themobile communication is not available via the mobile antenna.
 7. Theexternal battery of claim 4, wherein the satellite communication unitcauses to perform the satellite communication with only a predeterminedcommunication partner in a case where the authentication unit fails theuser authentication.
 8. The external battery of claim 2, furthercomprising: a signal reception unit that receives a positioning signalfrom a satellite in a case where the selection unit selects thecommunication mode.
 9. The external battery of claim 8, wherein thesignal reception unit receives the positioning signal of a plurality offrequency bands.
 10. The external battery of claim 1, furthercomprising: a measurement unit that measures values of biologicalinformation.
 11. The external battery of 10 claim 1, wherein thesatellite communication channel is a communication channel using an Sband for a communication frequency band.
 12. The external battery ofclaim 1, wherein the satellite communication channel is a communicationchannel via a quasi-zenith satellite.
 13. The external battery of claim1, further comprising: an information memory unit that stores routeinformation showing an escape route.
 14. A satellite communicationterminal comprising the external battery of claim
 1. 15. A satellitecommunication terminal having a mobile communication terminal and anexternal battery that charges the mobile communication terminal, whereinthe external battery includes: an electricity storage unit that storeselectric power; a charging unit that supplies the electric power storedin the electricity storage unit to the mobile communication terminal tocharge the mobile communication terminal; a satellite antenna to be usedwhen performing satellite communication via a satellite communicationchannel; and a satellite communication unit that causes the mobilecommunication terminal to perform the satellite communication via thesatellite antenna.